1. Field of the Invention
This invention relates to a safety control system for a turbocharged engine. In particular, the invention relates to a system for preventing damage to an internal combustion engine due to excess pressures generated by a turbocharger.
2. Description of the Prior Art
In a carbureted, turbocharged internal combustion engine, unsafe operating conditions may develop if the turbocharging system is not controlled. Such an unsafe condition occurs, for example, when the throttle is open to increase power output of the engine. This increased power output commensurately increases the exhaust gas which drives the turbine of the turbocharger thereby significantly increasing the supply of supercharged fuel air mixture to the combustion chamber. Under certain engine conditions, this supply of supercharged air will be greater than is required and may cause damage to both the engine and the turbocharger.
Conventionally, the problem created by a significant increase in volume of exhaust gas driving the turbocharger turbine has been alleviated by incorporating a waste gate valve in the exhaust manifold to provide means for bypassing the turbine. The waste gate valve relieves the volume and pressure of exhaust gas when they exceed a predetermined maximum. However, because conventional waste gate valves have failed, a more complete system for protecting the engine and turbocharger is necessary. The present invention provides an improved safety control system for a turbocharger in a carbureted internal combustion engine which controls the volume of exhaust gas acting on the turbine of the turbocharger and the volume of fuel-air mixture in the intake manifold, both in response to the output pressure of the turbocharger compressor. The present invention provides increased operating reliability over conventional safety systems which only incorporate an exhaust waste gate valve.